To protect Gruna, the HWSK Mulde provides for the repair of the existing dyke and the closing of the gap through the construction of a new ring dyke in the immediate vicinity of the village.

The length of the new section is approx. 1,282 m, the repair section is 1,475 m long. The investigation area for the environmental impact study was set at 404 ha for a comprehensive assessment of the operational impacts in particular. Extensive mapping of biotope and habitat types as well as of the animal groups amphibians, reptiles, mammals, breeding birds and winter visitors as well as butterflies was carried out.

In addition to the environmental impact study, the following nature conservation planning was prepared:

• Species protection law assessment
• Landscape conservation plan
• FFH impact assessment for the site "Vereinigte Mulde und Muldeauen" (United Mulde and Mulde floodplains)
  (EU No. 4340-302; No. 65E)
• SPA impact assessment for the SPA "Vereinigte Mulde
  (EU No. 4340-451; No. 19)